Knitting-machine cam



(No Model.)

J. W. RIST.

KNITTING MACHINE 0AM.

No. 244,079. Patented July 12, 1881.

N4 PETERs PholwLiQlmgnphen Washington. D c.

UNITED STATES PATENT OFFICE.

JOEL W. RIST, OF OHICOPEE FALLS, MASSACHUSETTS.

KNITTING-MACHINE CAM.

SPECIFICATION forming part of Letters Patent No. 244,079, dated July 12, 1881.

Application filed May 2, 1881. (No model.)

em'ent in Knitting-Machine Cams, of which the following is a full, clear, and exact specification and description, reference being had to the accompanying drawings,-

making a part of this specification.

The object of my invention is to prevent the needles inaknitting-machine from being forced down below their normal position which they.

usually occupy after the stitches have been formed thereon by the advance cam in each movement of the carriage to and fro, which downward movement of the needles causes a drag or unnecessary strain upon the yarn, and also causes an additional and useless friction of the parts in the ordinary machines; and I accomplish this by the mechanism and in the manner substantially as hereinafter de{ scribed, the needles themselves, in the operation of knitting, being the primary means usedin accomplishing the desired result.

Figure I is a reverse plan View of the plate and lock of a straight-knitting machine having my invention applied at one end. Fig. II is a lower edge view of the same with re1ief-= cam in section at line B. Fig. III is a plan .view of the index and fastening-nut connected with the eccentric and stud. Fig. IV is a re-= verse plan view, showing the eccentric and stud used in the ordinary machine, and Fig.;

1 although the latter is as practicable when used My invention relates to that class of knitting-machines which is provided with a lock-= V is a side view of the same.

ing or wing cams similar to that shown at A, one each side the elevating-cam 2 and with their small ends downward. The cam 2 acts at each reciprocating movement of the carriage to raise the needles; but the other cams depress them, the cam A,when the movement of the carriage is in the direction of the These cams have heretofore arrow, acting against the shanks of the needles to draw them down, and the corresponding cam, on the opposite side of the cam 2, operating to draw the needles down when the carriage is moving in the opposite direction.

In the ordinary machines of this class the cams A, one each side the elevating-cam 2, are just alike and act alternately, the rear cam, in each movement of the carriage, operating to depress the needles. In either movement of the carriage the advance cam is the idle one, and the other or rear cam is the active one. Ordinarily the depressing-cams are secured in position at the same height, and in the opera: tion of knitting the needle-shanks are consequently compelled to pass down beneath the forward or idle cam to the same extent that they are forced down by the rear and active cam. The elasticity of the yarn, after the stitches have been formed, has the effect to hold the shanks of the needles in a position a little elevated above the lower ends of the cams A, as shown at b in Fig. I.

I have shown but one of the ordinary depressing-cams A in the illustration or drawings, (which have always been arranged to slide bodily up and down on the plate,) because the use of my invention is intended to dispense entirely with this description of bodily-sliding cam, either at one or both ends of the lock-plate, so that the ordinary depressingcam A is shown on one side of the elevatingcam 2 and my invention shown on the other,

at both ends of the lock-plate as at one end only.

In the drawings, 12 denotes the lock-plate of an ordinary straight-knitting machine of this class, and 2 denotes the elevating-cam, or cam which raises the needles by operating against the shanks, and arranged in the ordinary manner.

A denotes the ordinary depressing-cam, as before mentioned, and held in any desired position by the stud or crank-pin 6, extending through the lock-plate and into a horizontal slot in the cam.

8 denotes a cam made according to my invention, which is secured to the lock-plate 12, with its lower edge parallel with the adjacent edge of the elevating-cam 2, and so as to slide on the lock-plate with its lower edgealways in substantially that position, by means of a stud or pivot, 11, moving in a slot in the lockplate, as shown in dotted lines at a, and with its lower portion hinged or connected with the lower end of an arm, 3, pivoted at its upper end to the lock-plate, as at 4..

The extreme lower end of the cam 8 may have one or more notches, as 7, made therein, and the cam is provided with an opening, as 5, into which the crank-pin 6 projects, so that when said crank-pin is turned into the proper positions the sliding motion of the cam -8 and the pivoted arm 3 will be limited more or less, as desired. By turning the crank-pin into proper position the said cam 8 may be fixed in a position with its upper end as shown in dotted lines at 20, and by turning the crank-pin '6.

upon the end of which the crank-pin is made,

and may be secured in any desired position to the outside of the carriage by a screw inserted through a slot therein, with an index, 15, and

knob 17, by which to turn the crank-pin and index into any desired relative positionwith the scale on the dial 14.

A check-nut, 16, turned upon the outer. end

of the shaft and firmly against the knob 17, secures the crank-pin and index in any desired position into which it may be turned.

A spring, 0, attached to the carriage and bearing against the cam, may be made to assist, if need be, in causing a quicker downward movement of the cam, although this is notessential to the practical and successful opera tion of the machine.

The lower end of the pivoted arm 3 may be: connected with the cam 8 in any desired man-;

a manner that the cam and its pivoted .arm will be moved down by the pressure of the needle-shanks against its side when theicarriage is passing in one direction, (indicated by a the arrow 5) or both may be moved up by thepressure of the needle-shanks against its lower end when moving in the opposite direction.

The operation of my invention is as follows: When the carriage is moving in the direction indicated by the arrow in Fig. I, the needles, having stitches thereon, occupy ..a position shown by their shanks at b, and in machines in which the cam A is used the needles are drawn still farther down by the cam A,which is in advance in the movement of the carriage. As the elevating-cam 2 passes in contact with the needle-shanks these are thrown upward to downward into its lowest position, the needleshanks being thus compelled to pass below and around the lower end of said cam, and

thus giving the yarn the desired and proper .tension in forming the stitches, until said cam has passed all the needles set for knitting. The elasticity of the yarn draws the needles upward, after-the cam has passed, into the position shown at b, in rear of the arrow, which isthe normal position of the needles when the knitting is finished; and when the movement of the carriage is reversed the shanks of the needles strike against the lower end of the cam 8 and move the latter upward into the position shown in dotted lines, s at the needles are not drawn down, as waficase by their contact with the lower en the :cam A in the other and. oppositemovement of the carriage;

strain upon'the yarn is entirely avoided, the

cam S'being converted into arelief-camto relieve the machine of its friction and wear of its 1 parts, occasioned by the drag uponthe vneedles, and the frequent breakage of the yarn.

This .arrangement of relief-camS is intended to take the place of the cam A, either atone or both ends of the lock-plate, as desired; but

.it will be found most advantageous to use the ging down of the needles hasflheretofore been avoided by making the mm A at-each end of m 5- the carriage movable, with an attachment connected therewith which-would strike against a stop fixedto the end of: the machineat each In the drawings a circular recess, 9, is made in the cam, with a correspondingly-shaped? tongue on the lower end of the arm to engage: in said recess; .but the lower end of the piv-; oted arm 3 may be connected with the lower: part of the cam 8 in any other desired manner, solong as the two are connected togetherin such alternate movement of the carriage-that is .tosay, the stop is attached to the stationary part .of the machine, at ,eachend, and when the carriage is moved in either direction tothe end of the machine the cam attachment strikes againstthe stop andthevcam is thereby shifted, and the advance cam is moved up sufficient- 1y to allow the shanksof the needles to pass beneath'without drawing them down, and thereby avoiding the straining of the yarn. These methods, how,ever,.of alternatelychangin g the .cams automatically by the movement of the carriage and stops connected therewith are very undesirable, owing to the fact that the mechanism for accomplishing the result is too complicated, requiring a greatnumber of parts necessarily somewhat delicate,.and are there- .foreextremely'liable to be broken and to be alternate movement of the carriage is also a very undesirable and unfavorable feature in the machine.

It will readily be seen by reference to the illustration that by simply substituting the cam 8 and the pivoted arm 3 in place of the ordinary triangular cam A no appliances are necessary to operate the cam 8, as the needles themselves operate it by their ordinary movements in knitting, and the invention is therefore entirely free from the objection of complication and consequent liability to get out of order.

As the needle-shanks pass down in contact with the lower edge of the cam 8 and. strike against the shoulders 7 in the lower end of said cam, the horizontal pressure of the needle-shanks against said shoulders assists in holding or retaining the cam in its lowest position until all said shanks have passed its lower end.

JOEL W. RIST.

Witnesses T. A. CURTIS, E. M. BIssELL. 

